The present invention relates to a battery, pack constructed with a plurality of prismatic battery modules arranged in a row and electrically connected with each other by means of connection modules.
FIG. 13 shows a conventional battery pack 41 constituted by arranging a plurality of prismatic battery modules in a row adjacent each other and connecting these electrically in series. End plates 43 are arranged at the opposite ends in the direction of juxtaposing arrangement of battery modules 42. The battery pack is unified by binding together the battery modules 42 with these two end plates 43 at either end by means of binding straps 44. The battery modules 42 are electrically connected by means of connection modules 46, 47 comprising a plurality of metal connecting elements that effect connection between connecting terminals 45 of adjacent battery modules 42. The connection modules 46, 47 are fixedly mounted in synthetic resin holders by insertion molding.
In one of the connection modules 46 at one end in the longitudinal direction of battery modules 42, there are also insertion-molded battery voltage detection terminals, while, in the other connection module 47 at the other end, only the metal connection elements are insertion-molded. The battery voltage detection terminals are connected to a battery voltage detection device 48.
However, with a battery pack 41 as described above, there are variations in the position of the connecting terminals 45 of the battery modules 42 in the direction orthogonal to the direction of arrangement of the battery modules 42. This means that the connecting terminals 45 are not positioned on the same plane, and when, in this condition, connecting terminals 45 are connected by directly screwing onto connection modules 46, 47, there is the problem that load acts on the connecting terminals 45, impairing the sealing characteristics between the connecting terminals 45 and the battery cases. A further problem was that, due to the variations in the thickness dimensions of the battery modules 42, it was impossible to eliminate variations in the positions of connecting terminals 45 in the direction of arrangement of battery modules 42. Such variations can sometimes be so large that screwing attachment and fixing of the connection modules 46, 47 is difficult.
A further problem was that, when such a battery pack 41 was arranged within the metal body of a vehicle, there was a risk that contact between the metal body and connecting terminals 45 of battery pack 41 resulting for example from a vehicle collision could result in the formation of a short circuit.
Yet a further problem was that, since there was a considerable voltage difference between adjacent connecting terminals 45, 45 that were not mutually connected and the spatial distance between these was short, there was a risk of a short circuit being generated if dust collected between them.